Membrane material based on amino resin and preparation method thereof

Abstract

The invention provides a membrane material based on amino resin and a preparation method of the membrane material. The membrane material comprises the following components: an amino resin matrix, a modified nanofiller, a polymer synergist and a porous support body, the dosage of the amino resin matrix is 50-80 parts by mass, the dosage of the modified nano filler is 5-15 parts by mass, and the dosage of the polymer synergist is 3-8 parts by mass. The preparation method comprises the following steps: preparing a membrane casting solution, coating and curing, and carrying out post-treatment to obtain the membrane material based on amino resin. Through the synergistic effect of the amino resin matrix, the modified nanofiller and the polymer synergist, the inherent advantages of the amino resin are maintained, and the permeability, the separation precision and the long-term stability of the membrane material are effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of membrane separation technology, specifically relating to an amino resin-based membrane material and its preparation method. Background Technology

[0002] Membrane separation technology, a novel separation technology developed in the 20th century, is now widely used in various industrial sectors. This technology uses selectively permeable membranes, driven by concentration, pressure, or potential differences, to separate, purify, and concentrate mixtures. Compared to traditional separation methods such as distillation, extraction, and adsorption, membrane separation processes offer significant advantages, including low energy consumption, ease of operation, and environmental friendliness.

[0003] Amino resins are an important class of polymer materials. Due to the large number of amino functional groups in their molecular structure, they possess excellent hydrophilicity and chemical stability, and are therefore widely used in the preparation of membrane materials. Common amino resins include urea-formaldehyde resin, melamine-formaldehyde resin, and phenylmelamine-formaldehyde resin. These resins form a three-dimensional network structure through the condensation reaction of amino and aldehyde groups, endowing the membrane materials with certain mechanical strength and chemical stability.

[0004] In practical applications, amino resin-based membrane materials face several pressing technical challenges. First, the high crosslinking density of amino resins results in an overly dense internal membrane structure, leading to significant mass transfer resistance and low permeate flux. For example, in some commercial nanofiltration membranes, water flux is often below 0.5 liters per square meter per hour, severely limiting membrane treatment efficiency. Second, traditional amino resin membranes lack selectivity, making it difficult to simultaneously achieve efficient separation of ions with different valence states. Furthermore, during long-term operation, especially under extreme acidic or alkaline conditions, membrane materials are prone to performance degradation, including functional group hydrolysis and crosslinking structure destruction, directly impacting membrane lifespan.

[0005] To improve the performance of amino resin membranes, researchers have made various attempts. A common approach is to introduce inorganic nanoparticles into the resin matrix, utilizing the additional transport channels formed by the nanoparticles to enhance membrane permeability. For example, some studies have introduced silica nanoparticles into polyamide composite membranes, controlling the size and distribution of the nanoparticles to regulate the membrane's pore structure. However, this method suffers from problems such as nanoparticle agglomeration and weak bonding at the matrix interface, which can easily lead to membrane structural defects and decreased selectivity.

[0006] Another approach to improvement is to introduce specific functional groups onto the membrane surface through chemical modification. Studies have reported the use of aminocyclodextrin to modify polyamide films, utilizing the cavity structure of cyclodextrin to improve membrane selectivity. However, due to steric hindrance, the grafting efficiency of this modification method is often low, and the modification effect is difficult to sustain. Some studies focus on optimizing post-treatment processes, such as treating the membrane with acidic solutions to remove unreacted oligomers and optimize the membrane pore structure. However, existing technologies do not provide precise control over post-treatment conditions, resulting in limited improvement in membrane performance and potentially affecting the membrane's mechanical strength.

[0007] In summary, existing amino resin membrane materials struggle to achieve a good balance between permeation performance, separation selectivity, and long-term stability. Especially in practical industrial applications, membrane materials need to simultaneously possess high permeation flux, excellent selectivity, and good durability, but current technologies do not offer a complete solution that can simultaneously meet these requirements. Therefore, there is a need to design an amino resin-based membrane material and its preparation method. Summary of the Invention

[0008] To overcome the shortcomings of the prior art, an amino resin-based membrane material and its preparation method are provided.

[0009] To achieve the above objectives, the present invention provides the following technical solution: An amino resin-based membrane material comprises the following components: an amino resin matrix, modified nanofillers, a polymer synergist, and a porous support; wherein the amino resin matrix is ​​used in an amount of 50 to 80 parts by weight, the modified nanofillers are used in an amount of 5 to 15 parts by weight, and the polymer synergist is used in an amount of 3 to 8 parts by weight.

[0010] The amino resin matrix is ​​at least one of urea-formaldehyde resin, melamine-formaldehyde resin, and benzo-melamine-formaldehyde resin.

[0011] The modified nanofiller is silica nanoparticles with surface-grafted aminosilane coupling agent; the particle size of the modified nanofiller is 20 to 100 nanometers; the grafting density of the modified nanofiller is 1.5 to 3.0 amino groups per square nanometer.

[0012] The polymer synergist is an amino-containing polyarylether ketone; the molecular weight of the amino-containing polyarylether ketone is 10,000 to 50,000 Daltons, and the amino content is 5% to 15%.

[0013] The porous support is a polyethersulfone ultrafiltration membrane or a polyacrylonitrile ultrafiltration membrane; the pore size of the porous support is 0.01 to 0.1 micrometers.

[0014] A method for preparing an amino resin-based membrane material, the method comprising the following steps: Preparation of casting solution: Dissolve amino resin prepolymer, modified nanofiller and polymer synergist in solvent, and stir at 40 to 60°C for 2 to 6 hours to form a homogeneous casting solution; Coating and curing: The casting solution is uniformly coated on the porous support and initially cured at 40 to 70°C for 0.5 to 2 hours, and then heat-treated at 80 to 120°C for 1 to 3 hours to form a cross-linked amino resin release layer. Post-treatment: The cured product is immersed in a 0.5 to 2.0 mol / L citric acid solution and treated at 50 to 70°C for 10 to 60 minutes. After removal, it is rinsed with deionized water and dried at 50 to 70°C for 8 to 16 hours to obtain an amino resin-based membrane material.

[0015] The preparation method of the modified nanofiller includes the following steps: dispersing nano-silica in anhydrous ethanol, adding ammonia and aminosilane coupling agent, reacting at 60 to 80°C for 4 to 8 hours, cooling to room temperature after the reaction, and obtaining modified nanofiller with amino content on the surface by centrifugation and washing.

[0016] The mass ratio of the nano-silica to the aminosilane coupling agent is 1:0.5 to 1:1.2; the aminosilane coupling agent is selected from at least one of 3-aminopropyltriethoxysilane and N-β-aminoethyl-γ-aminopropyltrimethoxysilane.

[0017] In the preparation of the casting solution, the solvent is N,N-dimethylformamide or N-methylpyrrolidone.

[0018] In the coating and curing process, the coating thickness is 100 to 300 micrometers, and the coating speed is 5 to 20 millimeters per second.

[0019] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1. This invention improves the permeation performance of membrane materials through the synergistic effect of an amino resin matrix and modified nanofillers. Traditional amino resin membranes suffer from excessively dense structures due to high crosslinking density. In contrast, the silica nanoparticles with surface-grafted aminosilane coupling agents in this invention form regular transport channels within the resin matrix. These channels ensure rapid passage of water molecules while effectively blocking the diffusion of salt ions, thereby achieving a simultaneous improvement in permeation flux and selectivity.

[0020] 2. The polymer synergist used in this invention optimizes the separation performance of the membrane material. The amino groups on the polymer synergist molecular chain can undergo cross-linking reactions with the functional groups in the amino resin matrix to form a denser and more uniform network structure. This structure not only improves the membrane's ability to retain multivalent ions but also maintains good water flux, overcoming the shortcomings of traditional amino resin membranes in terms of separation selectivity.

[0021] 3. This invention enhances the mechanical strength and stability of the membrane material through the organic combination of the porous support and the separation layer. The polyethersulfone ultrafiltration membrane or polyacrylonitrile ultrafiltration membrane serves as the support layer, providing a stable substrate for the amino resin separation layer. The amino resin separation layer, in turn, is tightly bonded to the support layer through chemical cross-linking. This composite structure effectively prevents delamination or damage that may occur during use.

[0022] 4. This invention significantly improves the dispersibility of nanofillers in a resin matrix by surface modification of nano-silica, grafting amino groups onto its surface. This modification effectively prevents the aggregation of nanoparticles, ensures the uniformity of the membrane structure, and thus improves the service life of the membrane material.

[0023] 5. The citric acid post-treatment process of this invention not only removes unreacted oligomers from the membrane and optimizes the membrane pore structure, but also forms a more stable amphoteric structure through the reaction of citric acid molecules with amino and imino functional groups in the membrane. This structure enables the membrane material to maintain stable separation performance in both acidic and alkaline environments. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the specific embodiments of this application, the sources of various main raw materials are briefly described as follows: Urea-formaldehyde resin prepolymer: Hubei Xinlantian New Material Co., Ltd. Melamine-formaldehyde resin prepolymer: Jinan Shengquan Group Co., Ltd., Model SQ-101 Benzyl melamine-formaldehyde resin prepolymer: Shanghai Banggao Chemical Co., Ltd., trade name BG-110 Nano-silica: Zhende Chemical Technology (Shanghai) Co., Ltd., CAS No.: 14808-60-7 3-Aminopropyltriethoxysilane: Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No.: 919-30-2 N-β-Aminoethyl-γ-aminopropyltrimethoxysilane: Hubei Xingyan New Material Technology Co., Ltd., CAS No.: 3069-29-2 Amino-containing polyaryletherketones: Evonik (China) Investment Co., Ltd., trade name VESTAKEEP® iG series Polyethersulfone ultrafiltration membrane: Hangzhou Cosma Membrane Technology Co., Ltd. Polyacrylonitrile ultrafiltration membrane: Shanghai Haolute Membrane Technology Co., Ltd. N,N-Dimethylformamide: Jinan Hongtai Weiye Trading Co., Ltd., CAS No.: 68-12-2 N-Methylpyrrolidone: Sinopharm Chemical Reagent Co., Ltd., CAS No.: 872-50-4 Anhydrous ethanol: Sinopharm Chemical Reagent Co., Ltd., CAS No.: 64-17-5 Ammonia solution: Sinopharm Chemical Reagent Co., Ltd., CAS No.: 1336-21-6 Citric acid: Aladdin Biochemical Technology Group Co., Ltd., CAS No.: 77-92-9 The technical solution of this application is as follows: An amino resin-based membrane material comprises the following components: an amino resin matrix, modified nanofillers, a polymer synergist, and a porous support; wherein the amino resin matrix is ​​used in an amount of 50 to 80 parts by weight, the modified nanofillers are used in an amount of 5 to 15 parts by weight, and the polymer synergist is used in an amount of 3 to 8 parts by weight.

[0026] The amino resin matrix is ​​at least one of urea-formaldehyde resin, melamine-formaldehyde resin, and benzo-melamine-formaldehyde resin.

[0027] The modified nanofiller is silica nanoparticles with surface-grafted aminosilane coupling agent; the particle size of the modified nanofiller is 20 to 100 nanometers; the grafting density of the modified nanofiller is 1.5 to 3.0 amino groups per square nanometer.

[0028] The polymer synergist is an amino-containing polyarylether ketone; the molecular weight of the amino-containing polyarylether ketone is 10,000 to 50,000 Daltons, and the amino content is 5% to 15%.

[0029] The porous support is a polyethersulfone ultrafiltration membrane or a polyacrylonitrile ultrafiltration membrane; the pore size of the porous support is 0.01 to 0.1 micrometers.

[0030] A method for preparing an amino resin-based membrane material, the method comprising the following steps: Preparation of casting solution: Dissolve amino resin prepolymer, modified nanofiller and polymer synergist in solvent, and stir at 40 to 60°C for 2 to 6 hours to form a homogeneous casting solution; Coating and curing: The casting solution is uniformly coated on the porous support and initially cured at 40 to 70°C for 0.5 to 2 hours, and then heat-treated at 80 to 120°C for 1 to 3 hours to form a cross-linked amino resin release layer. Post-treatment: The cured product is immersed in a 0.5 to 2.0 mol / L citric acid solution and treated at 50 to 70°C for 10 to 60 minutes. After removal, it is rinsed with deionized water and dried at 50 to 70°C for 8 to 16 hours to obtain an amino resin-based membrane material.

[0031] The preparation method of the modified nanofiller includes the following steps: dispersing nano-silica in anhydrous ethanol, adding ammonia and aminosilane coupling agent, reacting at 60 to 80°C for 4 to 8 hours, cooling to room temperature after the reaction, and obtaining modified nanofiller with amino content on the surface by centrifugation and washing.

[0032] The mass ratio of the nano-silica to the aminosilane coupling agent is 1:0.5 to 1:1.2; the aminosilane coupling agent is selected from at least one of 3-aminopropyltriethoxysilane and N-β-aminoethyl-γ-aminopropyltrimethoxysilane.

[0033] In the preparation of the casting solution, the solvent is N,N-dimethylformamide or N-methylpyrrolidone.

[0034] In the coating and curing process, the coating thickness is 100 to 300 micrometers, and the coating speed is 5 to 20 millimeters per second.

[0035] This invention utilizes the synergistic effect of an amino resin matrix, modified nanofillers, and polymer synergists to effectively improve the permeation performance, separation accuracy, and long-term stability of membrane materials while maintaining the inherent advantages of amino resins. The invented amino resin matrix, as the main film-forming substance, provides basic separation functionality; the modified nanofillers construct efficient transport channels; and the polymer synergists enhance separation selectivity. The synergistic effect of these three components enables the membrane material to maintain high permeation flux while possessing excellent separation performance and long-term stability.

[0036] The present invention will be described in detail below through examples and comparative examples, but the scope of protection of the present invention is not limited to these examples. Unless otherwise specified, the chemical reagents and raw materials used in the following examples and comparative examples are all conventional commercially available products.

[0037] Example 1: This example describes the preparation of an amino resin-based membrane material. The specific steps are as follows: First, a modified nanofiller is prepared. Nano-silica is dispersed in anhydrous ethanol, and ammonia and 3-aminopropyltriethoxysilane are added. The mass ratio of nano-silica to aminosilane coupling agent is 1:0.5. The reaction is carried out at 80 degrees Celsius for 6 hours. After the reaction is completed, the mixture is cooled to room temperature and centrifuged and washed to obtain a modified nanofiller with amino groups on the surface.

[0038] Then, a casting solution was prepared by dissolving 80 parts by mass of urea-formaldehyde resin prepolymer, 10 parts by mass of modified nanofiller, and 3 parts by mass of amino-containing polyarylether ketone polymer synergist in an appropriate amount of N,N-dimethylformamide. The casting solution contained 10% by mass of amino resin prepolymer, 5% by mass of modified nanofiller, and 1.75% by mass of polymer synergist. The solution was stirred at 60 degrees Celsius for 4 hours to form a homogeneous casting solution.

[0039] Next, coating and curing are carried out. The casting solution is scraped onto the polyethersulfone ultrafiltration membrane support at a speed of 20 mm per second, with a coating thickness of 100 micrometers. It is first pre-cured at 55 degrees Celsius for 0.5 hours, and then heat-treated at 120 degrees Celsius for 2 hours to form a cross-linked amino resin separation layer.

[0040] Finally, post-treatment was performed by immersing the cured membrane in a 0.5 mol / L citric acid solution and treating it at 70 degrees Celsius for 35 minutes. After removal, it was rinsed with deionized water and dried at 50 degrees Celsius for 16 hours to obtain an amino resin-based membrane material.

[0041] Example 2: In this example, the similarities to Example 1 will not be repeated, and the differences are as follows: In this embodiment, an amino resin-based membrane material is prepared using the following specific steps: First, a modified nanofiller is prepared by dispersing nano-silica in anhydrous ethanol, adding ammonia and N-β-aminoethyl-γ-aminopropyltrimethoxysilane, wherein the mass ratio of nano-silica to aminosilane coupling agent is 1:1.2. The reaction is carried out at 60 degrees Celsius for 8 hours. After the reaction is completed, the mixture is cooled to room temperature and centrifuged and washed to obtain a modified nanofiller with amino groups on its surface.

[0042] Then, a casting solution was prepared by taking 50 parts by mass of melamine-formaldehyde resin prepolymer, 15 parts by mass of modified nanofiller, and 8 parts by mass of amino-containing polyaryletherketone polymer synergist, and dissolving them in an appropriate amount of N-methylpyrrolidone. The casting solution contained 30% by mass of amino resin prepolymer, 1% by mass of modified nanofiller, and 0.5% by mass of polymer synergist. The solution was stirred at 40 degrees Celsius for 6 hours to form a homogeneous casting solution.

[0043] Next, coating and curing are carried out. The casting solution is scraped onto the polyacrylonitrile ultrafiltration membrane support at a speed of 5 mm per second, with a coating thickness of 300 micrometers. It is first pre-cured at 40 degrees Celsius for 2 hours, and then heat-treated at 80 degrees Celsius for 3 hours to form a cross-linked amino resin separation layer.

[0044] Finally, post-treatment was performed by immersing the cured membrane in a 2.0 mol / L citric acid solution and treating it at 50 degrees Celsius for 60 minutes. After removal, it was rinsed with deionized water and dried at 70 degrees Celsius for 8 hours to obtain an amino resin-based membrane material.

[0045] Example 3: In this example, the similarities to Example 1 will not be repeated, and the differences are as follows: In this embodiment, an amino resin-based membrane material is prepared. The specific steps are as follows: First, a modified nanofiller is prepared. Nano-silica is dispersed in anhydrous ethanol, and ammonia and 3-aminopropyltriethoxysilane are added. The mass ratio of nano-silica to aminosilane coupling agent is 1:0.85. The reaction is carried out at 70 degrees Celsius for 4 hours. After the reaction is completed, the mixture is cooled to room temperature and centrifuged and washed to obtain a modified nanofiller with amino-containing surface.

[0046] Then, a casting solution was prepared by taking 65 parts by mass of benzo-melamine-formaldehyde resin prepolymer, 5 parts by mass of modified nanofiller, and 5.5 parts by mass of amino-containing polyarylether ketone polymer synergist, and dissolving them in an appropriate amount of N,N-dimethylformamide. The casting solution contained 20% by mass of amino resin prepolymer, 3% by mass of modified nanofiller, and 3% by mass of polymer synergist. The solution was stirred at 50 degrees Celsius for 2 hours to form a homogeneous casting solution.

[0047] Next, coating and curing are carried out. The casting solution is scraped onto the polyethersulfone ultrafiltration membrane support at a speed of 12.5 mm per second, with a coating thickness of 200 micrometers. It is first pre-cured at 70 degrees Celsius for 1.25 hours, and then heat-treated at 100 degrees Celsius for 1 hour to form a cross-linked amino resin separation layer.

[0048] Finally, post-treatment was performed by immersing the cured membrane in a 1.25 mol / L citric acid solution and treating it at 60 degrees Celsius for 10 minutes. After removal, it was rinsed with deionized water and dried at 60 degrees Celsius for 12 hours to obtain an amino resin-based membrane material.

[0049] Comparative Example 1: The similarities to Example 1 will not be repeated here; the differences are as follows: No modified nanofillers are added; only an amino resin matrix and polymer synergists are used.

[0050] Comparative Example 2: The similarities to Example 1 will not be repeated here; the differences are as follows: No polymer synergists are added; only an amino resin matrix and modified nanofillers are used.

[0051] Comparative Example 3: The similarities to Example 1 will not be repeated here; the differences are as follows: The post-processing steps are omitted, namely, soaking in citric acid solution and drying are not performed.

[0052] Comparative Example 4: The similarities to Example 1 will not be repeated here; the differences are as follows: Unmodified nano-silica was used instead of modified nanofillers.

[0053] Comparative Example 5: The similarities to Example 1 will not be repeated here; the differences are as follows: The mass ratio of nano-silica to aminosilane coupling agent was changed to 1:0.3.

[0054] Comparative Example 6: The similarities to Example 1 will not be repeated here; the differences are as follows: The mass ratio of amino resin matrix to modified nanofiller was changed, with the amino resin matrix being 40 parts by mass and the modified nanofiller being 20 parts by mass. Performance test results and analysis: The membrane materials prepared in Examples 1 to 3 and Comparative Examples 1 to 6 were subjected to performance tests, including water flux, salt rejection rate, and acid stability. Water flux was tested using deionized water at a pressure of 0.5 MPa, and the volume of water passing through the membrane per unit time was recorded. Salt rejection rate was tested using a 1000 mg / L magnesium chloride and sodium chloride solution, and the salt concentrations of the feed and permeate were measured at the same pressure to calculate the rejection rate. Acid stability was tested by immersing the membrane in a 3% hydrochloric acid solution for 48 hours, followed by re-measuring the water flux and salt rejection rate to calculate the performance retention rate. All tests were performed at room temperature, and each sample was repeated three times, with the average value taken. The specific test results are shown in Table 1.

[0055] Table 1 Analysis of Test Results

[0056] As can be seen from Table 1, the membrane materials prepared in Examples 1 to 3 all exhibited high water flux and salt rejection rates, and also maintained high performance after acid treatment. This indicates that the present invention achieves a balanced improvement in permeability and separation selectivity through the synergistic effect of amino resin matrix, modified nanofiller and polymer synergist.

[0057] In Example 1, a high content of amino resin matrix and modified nanofiller, combined with optimized process parameters, resulted in an effective transport channel in the membrane structure, achieving a water flux of 8.6 L / m²·h·bar while maintaining a magnesium chloride rejection rate of 98.5%. This was attributed to the uniform dispersion and interfacial bonding of the modified nanofiller within the resin matrix. In Example 2, although the amount of amino resin matrix was lower, high water flux and rejection rate were still achieved by adjusting the component ratios and process conditions, demonstrating the good adaptability of the formulation design of this invention. Example 3, using a combination of intermediate parameters, exhibited balanced performance, with a performance retention rate as high as 99% after acid stabilization, indicating that citric acid post-treatment effectively optimized the membrane pore structure and chemical stability.

[0058] Comparative Example 1 showed a significant decrease in water flux and rejection rate due to the absence of modified nanofillers. This was because the lack of transport channels formed by nanofillers resulted in an overly dense membrane structure. Furthermore, the absence of nanofillers also affected the membrane's stability in acidic environments.

[0059] Comparative Example 2, without the addition of a polymer synergist, had lower water flux and rejection rate than the Example. This indicates that the polymer synergist plays an important role in enhancing the selectivity and structural integrity of the membrane, and the cross-linking reaction between the amino groups on its molecular chain and the resin matrix optimizes the membrane network structure.

[0060] Comparative Example 3 omitted the post-treatment step and its performance was between that of Example 1 and Comparative Example 1, but its acid stability was poor. This indicates that the citric acid post-treatment not only removes oligomers, but also forms a bipolar structure through the reaction, which improves the durability of the membrane under extreme conditions.

[0061] Comparative Example 4 uses unmodified nanofillers, and its performance is significantly worse than that of Example 1. This is because unmodified fillers are prone to agglomeration, leading to membrane structure defects and reduced selectivity.

[0062] Comparative Examples 5 and 6, by changing key parameters beyond the scope of this invention, further deteriorated the performance. An excessively low mass ratio would affect the modification effect, and an imbalance in the component ratio would disrupt the uniformity of the membrane structure.

[0063] This application achieves simultaneous improvement in membrane material permeation performance, separation accuracy, and long-term stability through the synergistic effect of amino resin matrix, modified nanofiller, and polymer synergist.

[0064] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An amino resin-based film material, characterized by, The film material comprises the following components: amino resin matrix, modified nano filler, polymer synergist and porous support; the amount of the amino resin matrix is 50 to 80 parts by mass, the amount of the modified nano filler is 5 to 15 parts by mass, and the amount of the polymer synergist is 3 to 8 parts by mass.

2. An amino resin-based film material according to claim 1, characterized in that, The amino resin matrix is at least one of urea-formaldehyde resin, melamine-formaldehyde resin and benzotriazine-formaldehyde resin.

3. An amino resin-based film material according to claim 1, characterized in that, The modified nano filler is silica nanoparticles grafted with amino silane coupling agent; the particle size of the modified nano filler is 20 to 100 nanometers; and the grafting density of the modified nano filler is 1.5 to 3.0 amino groups per square nanometer.

4. An amino resin-based film material according to claim 1, characterized by The polymer synergist is amino-containing polyaryletherketone; the molecular weight of the amino-containing polyaryletherketone is 10,000 to 50,000 Dalton, and the amino content is 5% to 15%.

5. An amino resin-based film material according to claim 1, characterized by The porous support is polyether sulfone ultrafiltration membrane or polyacrylonitrile ultrafiltration membrane; and the pore size of the porous support is 0.01 to 0.1 micrometers.

6. A process for the production of an amino resin-based film material according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: Preparation of casting solution: dissolving amino resin prepolymer, modified nano filler and polymer synergist in a solvent, stirring at 40 to 60°C for 2 to 6 hours to form a homogeneous casting solution; Coating and curing: uniformly coating the casting solution on the porous support, preliminarily curing at 40 to 70°C for 0.5 to 2 hours, and then heat treating at 80 to 120°C for 1 to 3 hours to form a crosslinked amino resin separation layer; Post-treatment: soaking the cured product in a 0.5 to 2.0 mol / L citric acid solution, treating at 50 to 70°C for 10 to 60 minutes, rinsing with deionized water after taking out, and drying at 50 to 70°C for 8 to 16 hours to obtain an amino resin-based film material.

7. The method for preparing an amino resin-based membrane material according to claim 6, characterized in that, The preparation method of the modified nano filler comprises the following steps: dispersing nano-silica in anhydrous ethanol, adding ammonia water and amino silane coupling agent, reacting at 60 to 80°C for 4 to 8 hours, cooling to room temperature after the reaction is completed, and washing by centrifugation to obtain modified nano filler containing amino groups on the surface.

8. The method for preparing an amino resin-based membrane material according to claim 7, characterized in that, The mass ratio of the nano-silica to the amino silane coupling agent is 1:0.5 to 1:1.2; and the amino silane coupling agent is at least one of 3-aminopropyltriethoxysilane and N-β-aminoethyl-γ-aminopropyltrimethoxysilane.

9. The method for preparing an amino resin-based membrane material according to claim 6, characterized in that, In the preparation of the casting solution, the solvent is N,N-dimethylformamide or N-methylpyrrolidone.

10. The method for preparing an amino resin-based membrane material according to claim 6, characterized in that, In the coating and curing, the coating thickness is 100 to 300 micrometers, and the coating speed is 5 to 20 millimeters per second.

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